The working of the kidneys of a person with diabetes is examined annually in connection with the follow-up examinations. If the kidneys’ ability to function is reduced, the tests can be carried out more frequently.
The operation of the kidneys is monitored with urine and blood tests. A blood sample is tested for the level of a protein called albumin in the urine. The blood test is conducted to find out the kidneys’ ability to filter by determining the blood creatine level (P-Krea) and the estimated glomerulal filtration rate (eGFR).
If necessary, it is possible to perform additional examinations to rule out other kidney diseases or tests to find out more information
Albuminuria is established using a sensitive method to measure the amount of albumin in urine. The easiest and most common way is to take a sample when you first have a pee in the morning to determine the urine albumin-creatinine ratio of the blood in urine. The abbreviation of urine albumin-creatinine ratio is U-AlbKrea (uACR or ACR in English). If the level is repeatedly over 3 mg/mmol, it is a sign of increased albumin secretion.
Because the secretion of albumin varies, a positive result must be verified and albuminuria must be established in two out of three samples in an examination performed over a period of 3–6 months.
The most exact method is to determine the secretion of albumin to the urine based on a night urine. The abbreviations used are cU-Alb or nU-Alb. A repeatedly higher than 20 µg/min level is a sign of increased albumin secretion.
Albuminuria is severe if U-AlbKrea is over 30 mg/mmol or if the level of albumin in night urine (cU-Alb) is over 200 µg/min. The same amount of protein is also present in a standard urine strip test (U-KemSeul).
In the hours leading up a urine test, you should avoid strenuous physical exertion, and the test should not be conducted during an inflammatory disease or the menstrual period.
Result | cU-Alb (µg/min) | U-AlbKrea (mg/mmol) |
|---|---|---|
Normal | < 20 | < 3 |
Mild albuminuria | 20 - 200 | 3 - 30 |
Severe albuminuria | > 200 | > 30 |
The kidneys’ ability to filter is measured by determining the plasma creatinine level of plasma in a blood sample. The abbreviation used in Finland is P-Krea. Creatinine is normally created by the metabolism of muscles, and it leaves the body through the kidneys. If the kidneys’ ability to filter is diminished, less creatinine is removed and the blood creatinine level increases. Normally, the blood creatinine level is below 100 μmol/l for men and below 90 μmol/l for women.
The creatinine level increases when the functioning of the kidneys decreases. Nonetheless, the result depends on the person’s age, size and, especially, muscle mass. The creatinine level is higher in a muscular person compared to someone with less muscle mass, even if the operation of their kidneys are similar.
This is why the operation of the kidneys is monitored on the basis of the estimated glomerular filtration rate. The abbreviation is eGFR. Based on person's gender and age, the laboratory will calculate the estimated glomerulal filtration rate. The person's eGFR result is lower, if kidneys' functions are decreasing.
Stage | GFR-class | eGFR(ml/min/1,73 m2) |
|---|---|---|
1 | Normal or high | ≥ 90 |
2 | Mild reduction | 60 - 89 |
3 | Moderate reduction | 30 - 59 |
4 | Severe reduction | 15 - 29 |
5 | Severe kidney damage | < 15 |
Updated 30.9.2023
